The invention relates generally to an ultrasound transducer, and more particularly, to a miniature ultrasound transducer fabricated using microelectromechanical system (MEMS) technology.
Ultrasound transducers use high-frequency sound waves to construct images. More specifically, ultrasonic images are produced by sound waves as the sound waves reflect off of interfaces between mechanically different structures. The typical ultrasound transducer both emits and receives such sound waves.
It is known that certain medical procedures do not permit a doctor to touch, feel, and/or look at tumor(s), tissue, and blood vessels in order to differentiate therebetween. Ultrasound systems have been found to be particularly useful in such procedures because the ultrasound system can provide the desired feedback to the doctor. Additionally, such ultrasound systems are widely available and relatively inexpensive.
However, present ultrasound systems and ultrasound transducers tend to be rather physically large and are therefore not ideally suited to all applications where needed. Moreover, due to their rather large size, ultrasound transducers cannot be readily incorporated into other medical devices such as, for example, catheters and probes. Hence, an ultrasound system and, more particularly, an ultrasound transducer of a relatively small size is desirable. MEMS technology is ideally suited to produce such a small ultrasonic transducer.
The present invention is an ultrasonic transducer for use in medical imaging. The ultrasonic transducer comprises a substrate having first and second surfaces. The substrate includes an aperture extending from the first surface to the second surface. Electronic circuitry is located on the first surface. A diaphragm is positioned at least partially within the aperture and in electrical communication with the electronic circuitry. The diaphragm has an arcuate shape that is a section of a sphere. The transducer further comprises a binder material in physical communication with the diaphragm and the substrate.
In accordance with another aspect of the present invention, a method of forming an ultrasonic transducer is provided. The method comprises the steps of providing a substrate with an aperture, covering the aperture with a film, and applying a differential pressure across the film to form a diaphragm having a shape that is a section of a sphere. The method further comprises the step of applying binding material to the diaphragm to maintain the spherical section shape of the diaphragm.
In accordance with another aspect, the present invention is a medical device for insertion into a mammalian body. The medical device comprises an insertable body portion and an ultrasonic transducing section on the body portion. The ultrasonic transducing section has a plurality of ultrasonic transducers. Each of the plurality of ultrasonic transducers comprises a substrate having first and second surfaces. The substrate includes an aperture extending from the first surface to the second surface. Electronic circuitry is located on the first surface. A diaphragm is located at least partially within the aperture and in electrical communication with the electronic circuitry. The diaphragm has an arcuate shape that is a section of a sphere. Each ultrasonic transducer further comprises a binder material in physical communication with the diaphragm and the substrate.